Why isn't hemodialysis used as first-line therapy for hyperkalemic emergencies?

• A. It's too slow to onset
• B. It has an immediate onset, but feasibility is limited by equipment and access
• C. It can worsen potassium shifts
• D. It is contraindicated in hyperkalemia

Answer: (B)

In hyperkalemic emergencies, you need rapid stabilization of the heart and quick reduction of extracellular potassium while arranging definitive removal. Dialysis is a highly effective way to remove potassium, especially in patients with renal failure or severe, refractory hyperkalemia, but it isn’t used as first-line because it requires a functioning dialysis setup, vascular access, and trained personnel. Those practical requirements mean dialysis can’t be started instantly in many urgent settings, so clinicians use faster, readily available measures (like calcium for membrane stabilization and insulin with glucose, sometimes beta-agonists or bicarbonate) to buy time and stabilize the patient while arranging dialysis. Once access and a machine are ready, dialysis provides rapid potassium removal.